Mechanick Exercises, or the Doctrine of Handy-Works

You should have them in several sizes, both because you may have work of different sizes and because it sometimes happens that a single piece of work has many parts joined and fitted together, some large and others small. You must also have them in several cuts because the Rough-toothed file original: "Rough Tooth'd File" cuts faster than the Bastard-toothed file, the Bastard-toothed file cuts faster than the Fine-toothed file, and the Fine-toothed file cuts faster than the Smooth-toothed file.

The Rough or Coarse-toothed file (which, if it is large, is called a Rubber) original: "Rubber"; a large, heavy file used for the initial rough shaping of metal. is used to remove the unevenness that the hammer made in your work during forging. The Bastard-toothed file is used to remove the deep cuts or file-strokes made by the Rough file. The Fine-toothed file is used to remove the cuts or file-strokes made by the Bastard file, and the Smooth file is used to remove those cuts or file-strokes made by the Fine file.

Thus, you see how files of various cuts follow one another until your work is as smooth as it can be made by filing. You may make it even smoother with Emery original: "Emerick"; a granular rock used as an abrasive for grinding and polishing., Tripoli original: "Tripoli"; a fine-grained sedimentary rock used as a polishing powder., etc. However, we will discuss that in its proper place, as it does not belong in this Section on Filing.

You must take care when using the Rough file to go very lightly over those dents the hammer made in your work, unless your work was forged to be somewhat thicker than necessary. Because those dents are irregularities in your work, if you were to file away as much material inside them as you do from the eminences or high spots, your work (whether it is straight or circular) would remain as irregular as it was before you filed it.

Furthermore, when you file the prominent or high parts of your work with your Coarse-cut file, you must also take care not to file away more than necessary. It is easy to be deceived because the Coarse file cuts deep and makes deep scratches in the work. Before you can remove those deep scratches with your finer-cut files, the places where the high spots were when your work was forged may themselves become dents from your ham- The text continues on the next page with the word "hammering."